1. Field of the Invention
The present invention relates to collapsible containers, and more particularly to containers for use in carrying and storing agricultural products, processed food products and like commercial articles which containers are collapsible for storage when not in use.
2. SUMMARY OF THE INVENTION
A collapsible container having high buckling strength is provided in which the container includes four side plates with the four side plates of the container including one plate formed in its inner surface with recessed portions along one end thereof and another side plate positioned adjacent to the recessed side plate and provided with hinge projections on one end thereof adjacent to the recessed side plate. Each of the recessed portions has a vertical pin supported by opposed walls defining the recessed portion. Each of the hinge projections includes grooved bearing portions which are open substantially toward the direction in which the grooved bearing portions are open when the plates are assembled, defined as "direction A" throughout the specification and claims. In addition, each of the hinge projections includes an elastic piece for rotatably retaining the vertical pin to thereby render the plates connectable into a collapsible assembly.
The hinge projection is adapted for abutting contact with an outer wall defining the recessed portion. This prevents the hinge projection from being easily removed from the recessed portion in a direction opposite to the above defined direction A and, accordingly, imparts increased buckling strength to the container, such as against a force acting thereon to force its side walls outward as when it is subjected to the weight of like containers stacked thereof. This feature further makes it possible to mold the two adjacent side plates separately, to shape both the recessed portion and hinge projection so that they are readily releasable from the molding dies and, consequently, to produce the container from synthetic resin in large quantities. Furthermore, because the hinge projection and the recessed portion are engageable with each other without permitting any part thereof to project from the outer surfaces of the constituent plates, the container is collapsible to a flat shape. In addition, the fact that the position of the grooved bearing portions relative to the inner surface of the side plate formed with the hinge projection is suitable determinable renders the bottom plate efficiently inwardly foldable.
Other features and advantages of the present invention will become apparent from the following description.
As described above, throughout the specification and appended claims, the term "direction A" is defined as the direction in which the grooved bearing portions are open when the plates are assembled, namely the direction inward of the side plate provided with the hinge projection. Accordingly, the hinge projection itself has no counterforce in a direction opposite to the direction A.
The present invention is in no way limited to the preferred embodiments to be described below with reference to the accompanying drawings.